Don't throw when options changed from falsy to object
Don't throw when options changed from falsy to object

Fixes #261 better than faded7993dc6a1338544029c34cce445d383fd62.

globexdesigns/react-dnd,tylercollier/react-dnd-demo,longlho/react-dnd,jgable/react-dnd,tylercollier/react-dnd-demo,globexdesigns/react-dnd,longlho/react-dnd,jgable/react-dnd